CCRL 40/15
Downloads and Statistics
April 18, 2021
Testing summary:
Total: 1'237'253 games
played by 2'822 programs

White wins: 424'164 (34.3%)
Black wins: 311'650 (25.2%)
Draws: 501'439 (40.5%)
White score: 54.5%

Engine Details

Options
Show each game results
GNU Chess 5.60 64-bit#109  (2813+16
−16
)Quote
Authors: Chua Kong-Sian (Singapore), Stuart Cracraft (USA), Lukas Geyer, Simon Waters, Michel Van den Bergh Links: Homepage, GnuWin32, Jim Ablett's compile, 5.07 Download
This is one of the 3 GNU Chess versions we tested: Compare them!
OpponentEloDiffResultsScoreLOSPerf
–   Alfil 15.7 64-bit3056+13
−13
(+243)1.5 − 4.5
(+0−3=3)
25.0%
1.5 / 6
0.0%
+90
0 = = = 0 0
–   Pirarucu 3.2.4 64-bit2994+22
−22
(+181)3 − 5
(+1−3=4)
37.5%
3.0 / 8
0.0%
+107
0 1 = = 0 = = 0
–   Hakkapeliitta 3.0 64-bit2953+12
−12
(+140)2 − 8
(+1−7=2)
20.0%
2.0 / 10
0.0%
−93
0 0 0 1 0 = 0 0 0 =
–   Rodent III 0.210 64-bit2936+19
−19
(+123)2 − 6
(+0−4=4)
25.0%
2.0 / 8
0.0%
−30
0 0 0 = 0 = = =
–   Berserk 3.2.1 64-bit2930+30
−30
(+117)5 − 7
(+1−3=8)
41.7%
5.0 / 12
0.0%
+69
0 = = = = 0 1 = = = 0 =
–   Bagatur 1.9 64-bit2928+23
−23
(+115)4 − 10
(+2−8=4)
28.6%
4.0 / 14
0.0%
−37
0 0 1 1 0 0 0 = 0 0 0 = = =
–   Rodent II 0.9.64 64-bit2915+22
−22
(+102)3 − 7
(+1−5=4)
30.0%
3.0 / 10
0.0%
−26
1 = = = = 0 0 0 0 0
–   Francesca MAD 0.29 64-bit2913+21
−21
(+100)4.5 − 7.5
(+1−4=7)
37.5%
4.5 / 12
0.0%
+28
0 1 = = = = 0 = 0 = = 0
–   Amoeba 2.6 64-bit2911+20
−20
(+98)2 − 6
(+0−4=4)
25.0%
2.0 / 8
0.0%
−55
0 = = = 0 = 0 0
–   Deep Junior 13.3 32-bit2908+15
−14
(+95)2.5 − 7.5
(+0−5=5)
25.0%
2.5 / 10
0.0%
−59
0 = = 0 = 0 = 0 = 0
–   Wasp 1.25 64-bit2907+22
−22
(+94)2 − 8
(+0−6=4)
20.0%
2.0 / 10
0.0%
−98
= 0 0 0 = 0 = = 0 0
–   Hannibal 1.2 32-bit2904+14
−14
(+91)4 − 6
(+1−3=6)
40.0%
4.0 / 10
0.0%
+35
0 0 = = = = = = 0 1
–   Francesca MAD 0.28 64-bit2900+24
−24
(+87)5.5 − 8.5
(+4−7=3)
39.3%
5.5 / 14
0.0%
+7
= 1 0 = 0 0 0 0 0 1 0 1 1 =
–   Atlas 3.91 64-bit2899+13
−13
(+86)5 − 7
(+2−4=6)
41.7%
5.0 / 12
0.0%
+33
= = 0 0 = = 1 = 0 = 0 1
–   chess22k 1.7 64-bit2898+22
−22
(+85)6 − 10
(+2−6=8)
37.5%
6.0 / 16
0.0%
+9
= = = 1 0 1 = = 0 = 0 0 0 = 0 =
–   EXchess 7.97b 64-bit2893+12
−12
(+80)5 − 5
(+3−3=4)
50.0%
5.0 / 10
0.0%
+75
0 0 1 1 = = 1 = 0 =
–   Winter 0.5 64-bit2893+17
−17
(+80)5.5 − 8.5
(+2−5=7)
39.3%
5.5 / 14
0.0%
+12
1 = 0 = 0 = = 1 = = 0 = 0 0
–   Spark 1.0 64-bit2891+12
−12
(+78)4.5 − 17.5
(+0−13=9)
20.5%
4.5 / 22
0.0%
−112
0 = 0 0 0 = = 0 = 0 = 0 0 0 = = 0 0 = 0 = 0
–   Deuterium 14.3.34.130 64-bit2890+12
−12
(+77)7 − 13
(+2−8=10)
35.0%
7.0 / 20
0.0%
−10
1 0 = = = = = 0 1 = 0 = = = 0 0 0 0 0 =
–   Gogobello 2.1 64-bit2890+19
−19
(+77)4 − 8
(+1−5=6)
33.3%
4.0 / 12
0.0%
−25
0 0 = = 1 = 0 = 0 0 = =
–   Demolito 2017-08-26 64-bit2889+20
−20
(+76)3.5 − 4.5
(+2−3=3)
43.8%
3.5 / 8
0.0%
+38
0 0 = = = 1 1 0
–   Cheng4 0.38 64-bit2889+23
−23
(+76)6.5 − 9.5
(+4−7=5)
40.6%
6.5 / 16
0.0%
+11
1 1 = = 0 = 0 = 0 0 0 0 = 1 0 1
–   Scorpio 2.8 64-bit2884+14
−14
(+71)3 − 9
(+0−6=6)
25.0%
3.0 / 12
0.0%
−84
0 = 0 = 0 = 0 = = = 0 0
–   Andscacs 0.71 64-bit2878+29
−30
(+65)2.5 − 7.5
(+0−5=5)
25.0%
2.5 / 10
0.0%
−83
0 = = 0 = 0 0 = = 0
–   FabChess 1.13 64-bit2878+21
−20
(+65)5 − 5
(+3−3=4)
50.0%
5.0 / 10
0.0%
+65
1 1 = 1 = 0 0 = 0 =
–   ChessBrainVB 3.202873+25
−25
(+60)3.5 − 6.5
(+2−5=3)
35.0%
3.5 / 10
0.0%
−39
0 1 = = 0 0 0 0 = 1
–   Amoeba 2.5 64-bit2872+23
−23
(+59)7.5 − 8.5
(+5−6=5)
46.9%
7.5 / 16
0.0%
+36
1 = 1 0 0 1 0 1 0 0 0 = = = = 1
–   Laser 1.2 64-bit2867+23
−23
(+54)5 − 5
(+3−3=4)
50.0%
5.0 / 10
0.0%
+49
= = 1 = 1 = 0 0 0 1
–   Vajolet2 1.45 64-bit2866+20
−20
(+53)9 − 16
(+3−10=12)
36.0%
9.0 / 25
0.0%
−32
= = 0 0 0 = = = 0 1 0 = 0 = 0 = 0 1 = = = 0 = 0 1
–   Scorpio 2.7.9 64-bit2866+25
−25
(+53)3.5 − 6.5
(+1−4=5)
35.0%
3.5 / 10
0.0%
−37
0 1 = 0 0 = 0 = = =
–   The Baron 3.44 64-bit2866+12
−12
(+53)5 − 3
(+2−0=6)
62.5%
5.0 / 8
0.0%
+120
= = = 1 = 1 = =
–   Thinker 5.4d Inert 64-bit2864+15
−15
(+51)0.5 − 1.5
(+0−1=1)
25.0%
0.5 / 2
0.0%
−91
0 =
–   Gaviota 1.0 64-bit2859+11
−11
(+46)1.5 − 0.5
(+1−0=1)
75.0%
1.5 / 2
0.0%
+203
1 =
–   Arasan 18.0 64-bit2859+26
−26
(+46)4.5 − 5.5
(+3−4=3)
45.0%
4.5 / 10
0.1%
+14
= 0 1 = = 1 0 0 0 1
–   Marvin 3.3.2 64-bit2857+21
−21
(+44)8.5 − 3.5
(+6−1=5)
70.8%
8.5 / 12
0.0%
+180
1 1 = 1 = 0 = 1 1 = = 1
–   Dirty 30Apr2017 64-bit2856+15
−15
(+43)6 − 10
(+3−7=6)
37.5%
6.0 / 16
0.0%
−38
0 0 0 0 = = 1 = = 0 = = 0 1 1 0
–   Zappa Mexico II 64-bit2853+10
−10
(+40)1 − 1
(+0−0=2)
50.0%
1.0 / 2
0.0%
+40
= =
–   MinkoChess 1.3 64-bit2852+14
−14
(+39)1 − 1
(+0−0=2)
50.0%
1.0 / 2
0.0%
+39
= =
–   EXchess 7.71b 64-bit2852+22
−22
(+39)9 − 5
(+6−2=6)
64.3%
9.0 / 14
0.2%
+131
1 0 = 1 1 = = 1 = = = 0 1 1
–   Tucano 7.06 64-bit2852+20
−20
(+39)8.5 − 11.5
(+4−7=9)
42.5%
8.5 / 20
0.1%
−5
= = 0 = 1 = = = 0 0 0 1 = 0 0 0 = 1 = 1
–   Pirarucu 2.3.8 64-bit2851+22
−22
(+38)2 − 6
(+1−5=2)
25.0%
2.0 / 8
0.3%
−142
0 0 0 0 0 = = 1
–   Rodent 1.7 64-bit2850+19
−19
(+37)3.5 − 4.5
(+2−3=3)
43.8%
3.5 / 8
0.2%
+4
1 = = 0 1 0 = 0
–   Toga II 3.02849+16
−16
(+36)0.5 − 1.5
(+0−1=1)
25.0%
0.5 / 2
0.1%
−121
= 0
–   Minic 1.39 64-bit2848+28
−28
(+35)4 − 8
(+2−6=4)
33.3%
4.0 / 12
1.6%
−76
= 1 0 0 0 0 = = 1 = 0 0
–   DisasterArea 1.65 64-bit2847+13
−13
(+34)4 − 6
(+2−4=4)
40.0%
4.0 / 10
0.1%
−29
= 0 0 0 1 = = = 0 1
–   Atlas 3.80 64-bit2847+14
−14
(+34)9.5 − 8.5
(+3−2=13)
52.8%
9.5 / 18
0.1%
+51
= = = 0 = = = 1 = = = 1 0 1 = = = =
–   Nemo 1.0.1 64-bit2847+12
−12
(+34)0.5 − 1.5
(+0−1=1)
25.0%
0.5 / 2
0.0%
−108
= 0
–   Asymptote 0.7 64-bit2844+21
−21
(+31)5 − 5
(+3−3=4)
50.0%
5.0 / 10
1.0%
+31
0 = = 0 1 1 = 1 0 =
–   Demolito 2017-06-18 64-bit2843+25
−25
(+30)4 − 6
(+3−5=2)
40.0%
4.0 / 10
2.4%
−42
= = 0 1 0 0 0 1 0 1
–   Arasan 17.4 64-bit2842+26
−26
(+29)2.5 − 0.5
(+2−0=1)
83.3%
2.5 / 3
3.3%
+273
1 1 =
–   Arasan 17.5 64-bit2840+25
−25
(+27)12.5 − 9.5
(+7−4=11)
56.8%
12.5 / 22
3.6%
+66
= = 1 = = 0 = = = 1 0 0 = 1 1 0 1 1 = 1 = =
–   The Baron 3.41 64-bit2837+22
−22
(+24)5 − 5
(+2−2=6)
50.0%
5.0 / 10
4.4%
+27
1 = = 1 = 0 = = = 0
–   Onno 1.2.70 64-bit2834+16
−16
(+21)2 − 0
(+2−0=0)
100.0%
2.0 / 2
3.7%
+INF
1 1
–   Weiss 1.0 64-bit2833+24
−24
(+20)9 − 7
(+4−2=10)
56.3%
9.0 / 16
9.4%
+51
0 = = 1 1 = = 1 = = 1 = = = 0 =
–   Winter 0.4a 64-bit2833+24
−24
(+20)7.5 − 4.5
(+4−1=7)
62.5%
7.5 / 12
8.5%
+91
= = 1 1 = = = 0 1 1 = =
–   Zurichess Neuchatel 64-bit2830+12
−12
(+17)6 − 4
(+4−2=4)
60.0%
6.0 / 10
4.9%
+75
= 1 0 = 1 1 0 = 1 =
–   Scorpio 2.7.8 64-bit2829+27
−27
(+16)5.5 − 4.5
(+2−1=7)
55.0%
5.5 / 10
16.1%
+43
= = = = = 1 = = 0 1
–   NirvanaChess 1.8 64-bit2827+25
−25
(+14)11.5 − 6.5
(+9−4=5)
63.9%
11.5 / 18
17.9%
+111
1 = 1 0 = = 1 1 0 = 1 1 1 1 0 = 0 1
–   DisasterArea 1.54 64-bit2826+18
−18
(+13)9.5 − 10.5
(+5−6=9)
47.5%
9.5 / 20
13.4%
−5
1 0 = = 1 1 = = = 0 1 = 0 1 = 0 0 0 = =
–   Tucano 7.00 64-bit2825+19
−19
(+12)5 − 5
(+2−2=6)
50.0%
5.0 / 10
18.5%
+12
0 = 0 1 = = = = = 1
–   Pedone 1.2 64-bit2825+26
−26
(+12)2.5 − 7.5
(+0−5=5)
25.0%
2.5 / 10
22.3%
−142
= = 0 = 0 = 0 0 0 =
–   chess22k 1.6 64-bit2823+28
−28
(+10)4 − 6
(+2−4=4)
40.0%
4.0 / 10
27.9%
−53
= 0 = 0 1 = 0 1 0 =
–   Murka 3 64-bit2823+12
−12
(+10)6 − 8
(+4−6=4)
42.9%
6.0 / 14
16.8%
−38
0 = 1 = 0 0 0 1 = = 0 1 1 0
–   Tucano 7.05 64-bit2823+28
−29
(+10)6 − 4
(+4−2=4)
60.0%
6.0 / 10
26.9%
+77
= 1 = 0 1 1 0 = = 1
–   DisasterArea 1.542821+31
−31
(+8)8.5 − 11.5
(+5−8=7)
42.5%
8.5 / 20
32.4%
−44
0 1 0 0 1 = 0 = 0 = 1 0 = = 0 = 0 1 = 1
–   Bagatur 1.8a 64-bit2821+28
−28
(+8)5.5 − 4.5
(+4−3=3)
55.0%
5.5 / 10
31.4%
+35
0 1 0 = 1 0 1 = 1 =
–   Tornado 6.0 64-bit2819+21
−21
(+6)12 − 18
(+6−12=12)
40.0%
12.0 / 30
32.7%
−56
0 1 0 = 0 0 = 1 0 0 1 1 0 = = 0 = 0 0 = = = = = = 0 1 0 1 =
–   Ethereal 8.37 64-bit2816+27
−27
(+3)1 − 5
(+0−4=2)
16.7%
1.0 / 6
43.9%
−232
0 0 0 = 0 =
–   EXchess 7.51b 64-bit2815+27
−27
(+2)8 − 12
(+4−8=8)
40.0%
8.0 / 20
44.7%
−61
0 0 1 1 = = 1 = = 1 = = 0 0 0 0 = 0 = 0
–   Dirty 10Apr2015 64-bit2805+24
−24
(−8)6.5 − 3.5
(+4−1=5)
65.0%
6.5 / 10
71.3%
+78
0 1 = 1 1 = 1 = = =
–   Rodent 1.6 64-bit2805+30
−30
(−8)1 − 3
(+1−3=0)
25.0%
1.0 / 4
69.2%
−242
0 0 1 0
–   Crafty 24.1 64-bit2803+22
−22
(−10)7 − 7
(+5−5=4)
50.0%
7.0 / 14
78.2%
−10
1 0 0 0 1 = = 1 1 = = 0 0 1
–   Cheng4 0.36c 64-bit2798+18
−18
(−15)13.5 − 7.5
(+8−2=11)
64.3%
13.5 / 21
90.0%
+70
= 0 = 1 = = 0 = 1 1 = = = 1 1 1 1 = = = 1
–   Pedone 1.1 64-bit2796+24
−24
(−17)3.5 − 4.5
(+2−3=3)
43.8%
3.5 / 8
87.4%
−59
= 0 1 = = 0 0 1
–   Zurichess Luzern 64-bit2792+24
−24
(−21)8 − 8
(+4−4=8)
50.0%
8.0 / 16
92.8%
−18
1 = = 0 = 1 = = = = = 0 0 1 0 1
–   Marvin 3.1.0 64-bit2791+21
−21
(−22)4.5 − 7.5
(+3−6=3)
37.5%
4.5 / 12
95.7%
−115
0 1 0 = 1 = 0 1 0 0 0 =
–   Atlas 3.70em 64-bit2787+22
−22
(−26)11.5 − 10.5
(+7−6=9)
52.3%
11.5 / 22
97.3%
−12
1 = = 1 = 0 = 1 0 = 0 = = = 1 0 0 0 = 1 1 1
–   Bobcat 6.4b 64-bit2787+24
−24
(−26)4.5 − 5.5
(+1−2=7)
45.0%
4.5 / 10
96.5%
−50
= = = 0 0 1 = = = =
–   Rybka 1.0 32-bit2786+14
−14
(−27)6 − 4
(+4−2=4)
60.0%
6.0 / 10
99.3%
+40
1 = 0 = 1 1 1 0 = =
–   The Baron 3.29 64-bit2785+18
−18
(−28)6 − 4
(+3−1=6)
60.0%
6.0 / 10
99.1%
+31
= = = = 1 1 = 0 = 1
–   RuyDos 1.1.0 64-bit2785+24
−24
(−28)4 − 4
(+3−3=2)
50.0%
4.0 / 8
97.1%
−33
0 1 1 1 0 = 0 =
–   Rodent 1.5 64-bit2784+21
−21
(−29)5 − 5
(+3−3=4)
50.0%
5.0 / 10
98.7%
−33
1 0 = 1 = = 0 0 = 1
–   RuyDos 1.1.6 64-bit2782+17
−17
(−31)4.5 − 5.5
(+3−4=3)
45.0%
4.5 / 10
99.6%
−62
0 1 = 1 0 = 0 0 = 1
–   Scorpio 2.7.6 64-bit2781+17
−17
(−32)1.5 − 4.5
(+0−3=3)
25.0%
1.5 / 6
99.7%
−179
= 0 0 = 0 =
–   Rhetoric 1.4.1 64-bit2775+17
−17
(−38)16.5 − 7.5
(+12−3=9)
68.8%
16.5 / 24
99.9%
+85
1 1 0 0 = 1 1 1 = 1 = 1 1 1 1 = = 1 = 1 0 = = =
–   RubiChess 1.1 64-bit2774+20
−20
(−39)2.5 − 5.5
(+1−4=3)
31.3%
2.5 / 8
99.9%
−157
0 1 0 0 = = = 0
–   Octochess r5190 64-bit2771+15
−15
(−42)5.5 − 6.5
(+3−4=5)
45.8%
5.5 / 12
100.0%
−69
1 0 1 1 0 = = 0 = 0 = =
–   Dirty 20Apr2013 64-bit2769+16
−16
(−44)4.5 − 3.5
(+3−2=3)
56.3%
4.5 / 8
100.0%
−1
0 1 0 = = 1 = 1
–   Zurichess Jura 64-bit2764+25
−25
(−49)6 − 4
(+5−3=2)
60.0%
6.0 / 10
99.9%
+24
1 1 0 0 = = 1 1 0 1
–   Winter 0.3 64-bit2764+25
−25
(−49)9.5 − 4.5
(+8−3=3)
67.9%
9.5 / 14
100.0%
+84
0 1 1 1 = = 1 1 1 0 0 = 1 1
–   RuyDos 1.0.27 64-bit2763+23
−23
(−50)6.5 − 3.5
(+5−2=3)
65.0%
6.5 / 10
100.0%
+45
1 1 0 1 1 = 1 = 0 =
–   Godel 4.0.7 64-bit2759+19
−19
(−54)4 − 4
(+2−2=4)
50.0%
4.0 / 8
100.0%
−54
= 0 0 1 1 = = =
–   Ethereal 8.28 64-bit2745+29
−29
(−68)5 − 5
(+3−3=4)
50.0%
5.0 / 10
100.0%
−72
1 = = 1 0 0 1 = 0 =
–   Amoeba 2.3 64-bit2743+27
−27
(−70)5 − 5
(+3−3=4)
50.0%
5.0 / 10
100.0%
−65
= 1 = 1 0 = = 0 0 1
–   Godel 3.4.9 64-bit2727+14
−14
(−86)3 − 1
(+3−1=0)
75.0%
3.0 / 4
100.0%
+141
1 1 0 1
–   Devel 2.00002724+14
−14
(−89)6 − 4
(+3−1=6)
60.0%
6.0 / 10
100.0%
−33
= = 1 = = 1 = 1 0 =
–   Amoeba 2.0 64-bit2721+26
−26
(−92)6.5 − 3.5
(+4−1=5)
65.0%
6.5 / 10
100.0%
−5
0 = = = 1 1 = = 1 1
–   Hakkapeliitta 2.0 64-bit2714+24
−25
(−99)10.5 − 1.5
(+10−1=1)
87.5%
10.5 / 12
100.0%
+244
1 1 1 = 1 0 1 1 1 1 1 1
–   Counter 2.9 64-bit2714+24
−24
(−99)7 − 3
(+5−1=4)
70.0%
7.0 / 10
100.0%
+33
1 1 = 1 = 0 1 1 = =
–   Amoeba 2.1 64-bit2709+29
−29
(−104)8 − 2
(+6−0=4)
80.0%
8.0 / 10
100.0%
+91
1 1 1 = = = 1 1 = 1
–   Cheese 1.9 64-bit2705+16
−16
(−108)13.5 − 6.5
(+9−2=9)
67.5%
13.5 / 20
100.0%
−1
1 1 0 = = = = 1 1 = 1 1 0 = = 1 1 = = 1
–   Pirarucu 2.2.2 64-bit2697+19
−19
(−116)5 − 5
(+1−1=8)
50.0%
5.0 / 10
100.0%
−116
= = = = 0 1 = = = =
–   Tucano 5.00 64-bit2678+18
−18
(−135)2 − 2
(+1−1=2)
50.0%
2.0 / 4
100.0%
−135
1 = = 0
–   Counter 2.8 64-bit2672+25
−25
(−141)4.5 − 3.5
(+3−2=3)
56.3%
4.5 / 8
100.0%
−98
= 0 0 1 1 1 = =
–   Djinn 1.021 64-bit2667+13
−13
(−146)3.5 − 0.5
(+3−0=1)
87.5%
3.5 / 4
100.0%
+144
1 1 = 1
–   RedQueen 1.1.97 64-bit2660+17
−17
(−153)3 − 1
(+3−1=0)
75.0%
3.0 / 4
100.0%
+74
1 0 1 1
–   Pawny 1.0 64-bit2659+17
−17
(−154)2 − 2
(+1−1=2)
50.0%
2.0 / 4
100.0%
−154
0 = = 1
–   RuyDos 1.0.2 64-bit2656+27
−27
(−157)6 − 4
(+3−1=6)
60.0%
6.0 / 10
100.0%
−105
1 = = 1 1 = = = 0 =
–   ECE X3 64-bit2645+16
−16
(−168)12 − 4
(+10−2=4)
75.0%
12.0 / 16
100.0%
+11
1 0 1 1 = = 1 1 1 = 1 1 0 = 1 1
–   Sjakk 2.2 64-bit2632+15
−15
(−181)3 − 1
(+2−0=2)
75.0%
3.0 / 4
100.0%
−23
1 = = 1
–   Alfil 13.1 64-bit2628+17
−17
(−185)4 − 0
(+4−0=0)
100.0%
4.0 / 4
100.0%
+INF
1 1 1 1
–   Igel 1.1 64-bit2628+26
−26
(−185)5 − 1
(+4−0=2)
83.3%
5.0 / 6
100.0%
+46
1 1 = = 1 1
–   Rotor 0.82628+17
−17
(−185)3.5 − 0.5
(+3−0=1)
87.5%
3.5 / 4
100.0%
+98
1 1 1 =
–   Pedone 0.5 64-bit2626+29
−29
(−187)3 − 1
(+3−1=0)
75.0%
3.0 / 4
100.0%
+39
0 1 1 1
–   Rodin 7.02600+17
−17
(−213)3.5 − 0.5
(+3−0=1)
87.5%
3.5 / 4
100.0%
+70
1 1 = 1
–   Glass 2.0 64-bit2597+13
−14
(−216)3.5 − 0.5
(+3−0=1)
87.5%
3.5 / 4
100.0%
+67
1 1 = 1

Rating changes by day

Rating changes with played games


Created in 2005-2013 by CCRL team
Last games added on April 18, 2021